Inventory Save is an option in Minecraft PE in the form of preservation of all things of a backpack even after You are killed. If you're lost from the crowd of some beast or zombie - Things will remain with you and nothing more will not be lost.

Inv Save is not an easy modification, and sufficiently profitable in the sense that You won't lose precious time to reclaim lost items after death. All will remain with You and you can start the path to the other side!